Chiral Catalyst Controlled Diastereoselection and Regioselection in Intramolecular Carbon−Hydrogen Insertion Reactions of Diazoacetates
作者:Michael P. Doyle、Alexey V. Kalinin、Doina G. Ene
DOI:10.1021/ja961682m
日期:1996.1.1
5R)-5-methyl-2-oxabicyclo[4.3.0]nonan-3-one with virtually complete selectivity by catalysis with dirhodium(II) tetrakis[methyl 2-oxopyrrolidine-5(S)-carboxylate], Rh2(5(S)-MEPY)4. Similarly high stereo- and regiocontrol is also achieved with enantiomerically pure trans-2-methylcyclohexyl diazoacetates. Product control from insertion...
取代的重氮乙酸环己酯或 2-辛基重氮乙酸酯的单个对映异构体与构型合适的手性甲酰胺二铑 (II) 催化剂相匹配,为合成具有特殊非对映和区域控制的内酯提供了一种有效的方法。对映异构纯 (1S,2R)-cis-2-methylcyclohexyl diazoacetate 形成 all-cis-(1R,5R,9R)-9-methyl-2-oxabicyclo[4.3.0]nonan-3-one 在反应中完全非对映控制由二铑(II)四[1-(3-苯基丙酰基)-2-氧代咪唑烷-4(R)-羧酸酯]、Rh2(4(S)-MPPIM)4催化,但构型不匹配导致产物混合. 相同的重氮乙酸酯通过使用四[甲基 2-氧代吡咯烷-5(S)-二铑 (II) 催化,几乎完全选择性地生成 (1S,5R)-5-methyl-2-oxabicyclo[4.3.0]nonan-3-one羧酸盐], Rh2(5(S)-MEPY)4。